"I thought about the decision long and hard and am very thankful to those responsible at Schalke for giving me this time. But now I've reached a decision I'm most happy about," Huntelaar said.

"I have always felt comfortable at Schalke, with the club and its fans. Now I want to send out a positive sign that I believe in our team."

Huntelaar was the Bundesliga's top-scorer last season with 29 goals in 32 games. He also set a club record with 48 goals across all competitions in a season.

The 29-year-old has 11 goals in all competitions this season.

Huntelaar joined Schalke from AC Milan in 2010. He previously played for Real Madrid, Ajax and Heerenveen.

Schalke is seventh in the Bundesliga at the halfway stage of the season and faces Turkish side Galatasaray in the Champions League round of 16.

The club has endured a disappointing end to 2012, getting knocked out of the German Cup by Mainz during a seven-game run without a win. Coach Huub Stevens departed the club on Dec. 16 after six league games without winning.